Create labels to organize Gmail
Intro
Creating and Managing Labels will help you to organize emails efficiently
Create labels
Left Click More on the left sidebar

Scroll down to bottom on the left sidebar

If you see the menu differently like the picture below, Left Click cogwheel to manage labels or + to create new label

Left Click Manage Labels or Create New Label

Type a name and optionally select a category for it to belong to and Left Click Create to finalize your changes

Now, you can organize emails by using the labels you added

After you create and use labels, you can manage the emails according to the circumstances